As a school leader, you will experience a situation in which someone refuses to buy in and contribute to a project. This decision to "draw the line" may not matter and your project continues anyway. On the other hand, the person refusing to move may actually halt progress.
In these situations, it is best to determine whether the line was "drawn in sand or concrete."
Lines drawn in concrete are another matter.
Lines drawn in concrete cost more.
Effective leaders quickly determine in which substance lines are drawn and work to move (or remove) them as the case may be.